Assembly system for two tubular parts capable of being locked and unlocked

ABSTRACT

The system permits two tubular parts ( 1, 2 ) to be assembled, the assembly being able to be locked or released, without a cumbersome device being required. It includes in particular a toothed crown ( 10, 20 ) on each of the two tubular parts ( 1, 2 ), each with a series of teeth ( 11, 21 ) disposing of straight radial shoulders ( 12 ) on the first toothed crown and angled shoulders ( 22 ) on the second toothed crown. This assembly is completed by a locking ring ( 30 ) disposing of teeth ( 31 ) designed to fit between the shoulders ( 12, 22 ) of the two crowns, once they have interlocked. Turning the locking ring ( 30 ) allows, using the angled locking faces ( 33 ) of the teeth ( 31 ), the two tubular parts ( 1, 2 ) to be locked together. A locating ring ( 40 ) may be used to center the parts and receive the shear loads due to a transversal mechanical change. The system may be applied for large tubular part assemblies that need to be dismantled.

This application claims priority based on International PatentApplication No. PCT/FR01/02156, entitled “Lockable and ReleasableAssembly System For Two Tubular Parts” by Joel Ricard, which claimspriority of French Patent Application Serial No. 00 08799, filed on Jul.6, 2000.

FIELD OF THE INVENTION

The invention concerns, in general, end to end assembly of two tubularparts and, in particular, large diameter pipes.

PRIOR ART AND THE PROBLEM IN QUESTION

In industry, there are several conventional and efficient means forend-to-end assembly of two tubular parts, including the following threeexamples.

A first means consists of fitting a flange to the end of each of the twopipes. The two pips are joined by means of a screw thread, such aslocking studs or bolts. This system is widely used and is particularlysturdy, and does not require any difficult machining. However, it istime consuming to implement and is cumbersome.

A second means consists of using the same flanges mentioned in theprevious paragraph, but to join them together by means of an externalcollar. This system is also sturdy, but also requires a considerableamount of time. In addition, the machined dimensions of the collardepend on the dimensions of the flanges and need to be accurate.Finally, it is quite cumbersome.

A third system consists of a threaded connection, which is to sayscrewing each end of the pipes to be connected into a same sleeve. Thissystem is also sturdy and takes up little space. It does not require anydifficult machining or a lot of time. However, it is more difficult todismantle.

The aim of the invention is therefore to overcome these drawbacks byoffering a compact system, that is sturdy and easy to implement and thatdoes not require precision machining.

SUMMARY OF THE INVENTION

To this end, the main subject of the invention is a lockable andreleasable end to end assembly system for two tubular parts of the samediameter, the system comprising:

a first toothed crown, attached to one end of the first of the twotubular parts to be assembled, and formed by a determined number N ofteeth, the ends of which each have a straight radial shoulder facingtowards the outside;

a second toothed crown, attached to the end of the second of the twotubular parts to be assembled, and formed of the same determined numberN of teeth, the ends of which each having an angled radial shoulder,with an angled clamping face forming a helicoidal ramp sectionstretching towards the outside, these teeth being separated from oneanother by a space at least as large as the teeth of the first crown,the teeth of the first crown being separated from one another by a spaceat least as large as the width of each tooth of the second crown; and

a locking ring formed by a section of tube whose internal diameter isslightly bigger than the diameter defined by the radial shoulders of theteeth of the two toothed crowns, this locking ring having the samenumber N of trapezoidal teeth and each having an angled clamping faceforming a helicoidal ramp section that is complementary to that of theangled shoulders of the second toothed crown, which is to say with thesame angle as that of the angled clamping faces of the shoulders of theteeth of the second toothed crown, the teeth of this ring being narrowerthan the space between the teeth of the second crown and beingpositioned at a distance equal to or greater than the width of the teethof the two toothed crowns, in order that they can fit between and overthe two toothed crowns and to penetrate, by rotation around the axis ofthe toothed crowns, the teeth its teeth between the respective shouldersof the teeth of the two toothed crowns until the assembly is locked.

In the principal embodiment of the invention, the ring's teeth each havea flexible attachment to the locking ring to leave a degree of freedomto the angled clamping faces of the teeth rotating around the axis ofthe toothed crowns.

In this case, it is preferable that these teeth are each formed by anindividual part separate from the locking ring, the flexible attachmentbeing formed by a narrower section of the tooth between the angledclamping face and a thrust face of the same tooth, which takes, by meansof a thrust pad, the thrust of the locking ring and thus defining the anelement of flexibility on which the thrust face and tooth body aresituated.

At least one slot in the tooth body may complete this embodiment tofasten the tooth to the locking ring, by means of a guide pin fixed tothe locking ring, in order to guide the relative sliding movement of thetooth with respect to the locking ring.

In the same case, it is also useful to use an releasing stop, fixed tothe locking ring, which bears on a face opposite the thrust face of thecorresponding tooth, in order to release the assembly by rotation of thelocking ring, in the opposite direction to that used to lock it.

In order to make the two parts to be assembled easier to position, it isuseful to use a centring ring whose external diameter is just smallerthan the internal diameter of the toothed crowns, and which is to beplaced inside of the toothed crowns. Furthermore, this ring receives theshear loads in the event of transversal mechanical loads being applied.

It is possible to use at least one locking screw that passes through thecentring ring, the two toothed crowns and the locking ring to lock thewhole assembly together.

LIST OF FIGURES

The invention and its various technical characteristics will be easierto understand after reading the following description, accompanied byseveral figures respectively showing:

FIG. 1, showing an exploded view of the system according to theinvention;

FIG. 2, showing in a cutaway view, the main elements of the inventionprior to assembly, the locking ring only shown partially;

FIG. 3, showing in a cutaway view, the main elements of the inventionafter assembly, the locking ring only shown partially;

FIG. 4, a partial view of the teeth used in the system according to theinvention;

FIG. 5, showing in a cutaway view, the details of a preferred embodimentof the system according to the invention; and

FIG. 6, a partial cross section, showing another detail of the preferredembodiment of the system according to the invention.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

In reference to FIG. 1, the two tubular parts, 1 and 2, of virtually thesame diameter, to be assembled, are each shown fitted with a toothedcrown respectively 10 and 20. In this embodiment, these toothed crowns10 and 20 are an integral part of the two tubular parts 1 and 2. This isonly one possible embodiment, these toothed crowns 10 and 20 may be madeseparately and subsequently fixed to the tubular parts 1 and 2.

These two assemblies are shown separated by a locking ring 30.

The toothed crown 10 of the first tubular part 1 is composed of adetermined number N of teeth 11, each disposing of a straight shoulder12 protruding outwards. Each of these shoulders 12 has a straightclamping face 13 perpendicular to the main axis of the tubular parts 1and 2 of the crowns and ring, 10, 20 and 30.

Correspondingly, the toothed crown 20 of the second tubular part 2 has asame number N of teeth 21, each disposing of an angled radial shoulder22 stretching outwards, in the same way as the shoulders 12 of the firsttoothed crown 10. The only difference is the presence of an angledclamping face 23 thus forming a helicoidal ramp section. It can beremarked that the teeth 11 and 21 of each toothed crown 10 and 20 areseparated from one another, which is to say on the same crown, by adistance at least as wide as the width of the teeth themselves 11 and21. In this way, the toothed crowns 10 and 20 can interlock with oneanother, the teeth of one fitting between the teeth of the other, theclearance being essentially for assembly purposes.

The third main element of the assembly system is therefore the lockingring 30, composed of a section of tube whose diameter is the same as theexternal diameter of the two tubular parts 1 and 2 to be assembled,slightly bigger than the diameter defined by the external edges of theshoulders 12 and 22 of the toothed crowns 10 and 20. This locking ring30 must be capable of covering the two-toothed crowns 10 and 20 whenassembled. It disposes, on its inside face 32, of a same determinednumber N of teeth 31. These teeth are trapezoidal in shape and dispose,among others, of a helicoidal ramp section shaped angled clamping face33. The angle of this clamping face 33 is the same as that of theclamping face 23 of the shoulders 22 of the second toothed crown 20.They are separated from one another by the same number of spaces, whichare at least as wide or slightly wider than the teeth 11 and 21 of thetwo-toothed crowns 10 and 20. Preferably, the width of the “tooth—spaceto the next tooth” print of the two-toothed crowns 10 and 20 or of the“tooth—space to the next tooth” print of the locking ring 30 are alsoequal.

In the representation shown in FIG. 1, a guide 40 is fitted onto thesecond tubular part 2. This guide is formed of a cylindrical sectionwhose external diameter is the same as the internal diameter of the twotubular parts 1 and 2. It is inserted beforehand into one of the twotubular parts 1 or 2, to make the parts easier to position with respectto one another, and possibly to take the shear loads in the case of theapplication of a transversal mechanical load.

FIG. 2 illustrates the positioning phase of the two tubular parts 1 and2, and especially the teeth II and 21 of the two toothed crowns of thesetubular parts 1 and 2. Of course, the teeth 11 of the first toothedcrown are positioned between the teeth 21 of the second toothed crown,so that they can mesh into one another. The locating ring, 40,positioned inside the second tubular part 2, allows the teeth 11 of thefirst toothed crown to be positioned so that the assembly can be made.

This same FIG. 2 also shows the teeth 31 of the locking ring, reference30 on FIG. 1. Each tooth is positioned against a tooth 21 of the secondtoothed crow, behind the shoulder of the 22 of the corresponding tooth.Consequently, their respective clamping faces 23 and 33 are positionedagainst one another.

FIG. 3 shows the entire assembly in the assembled and locked position.To this end, the end of each tooth 11 and 21 is chamfered to make thetwo-toothed crowns 10 and 20 easier to mesh together. The teeth 11 and21 therefore fit into one another, and the shoulders 12 or 22 of eachset of teeth come into contact with the tubular part opposite them.

Furthermore, each tooth 31 undergoes a helicoidal movement between therespective shoulders 12 and 22 of the two-toothed crowns. In otherterms, the locking ring has rotated around the axis of the tubular parts1 and 2.

This movement is shown more clearly in FIG. 4. In fact, the helicoidalmovement mentioned is shown by the arrow. The position, shown in dottedlines, is that of the tooth 31 when the assembly is made, which is tosay when the parts 1 and 2 are fastened to one another. In this secondposition, the respective angled clamping faces 23 and 33 of the angledshoulders 22 and the teeth 31 have slid against one another, moving fromthe smallest end to the largest end of the trapezium shape of the twoparts. Consequently, the tooth 31 tends to separate the shoulders 12 and22 and bring the two tubular parts 1 and 2 together so that they pressedagainst one another. In other terms, the helicoidal movement of thetooth 31 caused by the rotation of the locking part 30 upon which theteeth 31 are positioned, causes another movement parallel to the axis ofthe tubular parts 1 and 2, as shown by the small offset between the twopositions of the tooth 31 shown in FIG. 4. Of course, the shape and inparticular the two heights of the teeth 31 are calculated to optimiseclamping.

In order that the attachment uses the maximum number of teeth possible,the machining of the two toothed crowns and the locking ring teeth mustbe precise and identical so that as many shoulders as possible are incontact. However, as the machining cannot be absolutely perfect, it issupposed that a number of the angled clamping faces will not be incontact with the others, whereas others will be as soon as the lockingring is rotated. One aspect of the invention is therefore to allow allof the teeth to be in, contact with their respective shoulder. To thisend, flexible attachments are used between the teeth 31 and the lockingring 30.

FIG. 5 permits a detail of a preferred embodiment of the invention to beshown. The flexible attachment means leave a degree of freedom, in asmall proportion, in the direction of the movement of the locking ringteeth, along the teeth 11 and 21, which is to say around the axis of theparts to be assembled 1 and 2. In FIG. 5, and for the purpose ofclarity, the locking ring is only shown as one of the N thrust pins 34that is part of this locking ring. On the other hand, the tooth 51 ismobile with respect to the locking ring. It can simply receive, by meansof a thrust face 52 and via a thrust pin 34, the thrust from the lockingring. A thrust pad 59 permits this thrust to be only transmitted to theend of the flexible attachment 54 of the tooth 51, defined by a reducedsection 53. The latter therefore defines a flexible part 54 and a toothbody 57.

It can therefore be understood that when the thrust caused by thelocking ring thrust pin 34 on the thrust face 52 of the tooth 51, theflexible part 54 can bend slightly under the resistance to the forwardmovement of the tooth 51, whose clamping face 33 comes into contact withand presses against the clamping face 23 of the corresponding angledshoulder. In this way, the first tooth 51, whose progression will bestopped by friction and the final blocking of the clamping faces 13 and23, will allow, due to the suppleness of its flexible part 54, the otherthrust pins 34 to continue to progress, in the aim of having as manyteeth 51 in contact and locked as possible.

FIG. 5 also shows two guide pins 36 that are fixed to the locking ringand with respect to which the tooth 51 can make a translation movement,thanks top two corresponding slots 55. An releasing stop 37, part of thelocking ring, is provided to bear onto a face 58 that is opposite thethrust face 52 of the tooth 51. In this way, when the locking ring isrotated, in the opposite direction to that used to lock it, each tooth51 can be released by the corresponding stop 37.

FIG. 6 shows how the different elements involved in this system arepositioned at the tooth 51 level. All of the elements of FIG. 5 can befound in FIG. 6. Each of the guide pins 36 are fixed to the locking ring30 and are each housed in the corresponding slot 55 of the tooth 51. Thethrust pad 59 receives the thrust from the thrust pin 34, which is inturn attached to the locking ring 30 by means of two screws 60. Onescrew 38 is screwed into a nut 39 which is seated on the centring ring40, inside the assembly. In this way, the complete clamping of the screw38 allows the centring ring 40, the teeth 11 and 21 of the toothedcrowns, the teeth 51 and the locking ring 30 to be clamped. It istherefore possible to lock the attachment of the two tubular parts 1 and2 to be joined. It is preferable to provide several clamping screws 38around the circumference. Such a system may be used to join tubularparts with diameters of 200 mm or more. The number of teeth used andtheir geometry depends on the loads involved.

It is useful to angle the angled clamping faces 23 and 33 of the angledshoulders 21 and the teeth 31 and 51 at around 4.5°. In fact, thetubular parts to be joined are most often subject to transversalmechanical stresses. The geometry of the system therefore permits themajority of the loads in the longitudinal axis of the parts to betransmitted.

1. A lockable and releasable assembly system for two tubular parts (1,2) of the same diameter, for end to end assembly, the system comprising:a first toothed crown (10), fixed to the end of the first of the twotubular parts (1), and formed by a determined number N of teeth (11),whose ends each have a straight radial shoulder (12), facing outwards; asecond toothed crown (20), fastened to the end of the second of the twotubular parts (2), formed by the same number N of teeth (21), whose endseach have an angled radial shoulder (22), with an angled clamping face(23), each forming an outward facing helicoidal ramp section, the teeth(21) of this second toothed crown (20) being separated by a distanceequal to or greater than the width of the teeth (11) of the firsttoothed crown (10), the teeth (11) of the first toothed crown (10) eachbeing separated from one another by a distance equal to or greater thanthe width of the teeth (21) of the second toothed crown (20); and alocking ring (30) composed of a tube section whose internal diameter isbigger than the external diameter defined by the shoulders (12, 22) ofthe two toothed crowns (10, 20), and each having a same determinednumber N of wedges (31, 51) and an angled clamping face (33) that iscomplementary to the clamping face (23) of the angled shoulders (22),which is to say at the same angle as the clamping face (23) of theshoulders (22) of the teeth (21) of the second toothed crown (20) and ata distance equal to or greater than the width of the teeth (21) of thesecond toothed crown (20), so that they can mesh between the toothedcrowns (10, 20) and by rotating around the axis of the toothed crowns(10, 20), make the teeth of the locking ring fit between the respectiveshoulders (12, 22) of the teeth (11, 21) of the two toothed crowns (10,20) until the assembly is locked, wherein the wedges (51) each have aflexible attachment with the locking ring (30) to give a degree offreedom to each clamping face (13, 23) of the wedges (51) rotatingaround the axis of the toothed crowns, the wedges (51) are each formedby a part separate from the locking ring (30), the flexible attachmentbeing formed by a reduced section (53) of the wedge (51) positionedbetween the angled clamping face (33) of the wedge (51) and a thrustface (52) of the same wedge (51) that can receive the thrust via athrust pad (59), a thrust pin (34) actuated by the locking ring (30),thus defining for each wedge (51) a flexible attachment (54) on whichthe thrust face (52) and a wedge (51) body (57) are located.
 2. Assemblysystem of claim 1, further comprising at least one slot (55) in the body(57) of the wedge (51), that permits a rotational movement of the wedge(51) via a guide pin (36) that is part of the locking ring (30) to guidethe wedge (51) in a relative sliding movement with respect to thelocking ring (30).
 3. Assembly system of claim 1, further comprising acentering ring (40) whose internal diameter is smaller than or equal tothe internal diameter of the toothed crowns (10, 20) and which ispositioned inside said crowns.
 4. Assembly system of claim 1, furthercomprising at least one release stop (37) that is fastened to thelocking ring (30) to bear onto a face (58) that is opposite the thrustface (52) of the wedge (51).